My MINI dealer recently installed a JCW head in my 2006 R53 after the prior "S" head got the spark plug threads stripped in cylinder two. My car has a Milltek Catback, CAI, GP intercooler, 15% pulley and a ECU tune by Jan Bruegemann prior to the head installation.

I asked them to install JCW spark plugs along with the head that are one stage cooler than the regular R53 plugs but they said it only warrants the cooler plug if bigger fuel injectors are installed. Therefore they installed the NGK BKR6EQUP plug for R53 instead of the cooler NGK BKR7EQUP for JCWs. They said the cooler plug will cause problems with my current set up unless I install injectors. I don't want to have the ECU retuned so I'm holding off on the injectors.

Do you guys think I should have cooler plugs on my current set up or not?

 

My best guess is yes. One step colder, the reason being, Jan's tune. What heat range plugs did the dealer pull out of the old head?

 

Not sure of the heat range but it was Iridium plugs from the prior owner. When I bought the car back then the prior owner had installed a MiniMania upgrade package that included the iridium plugs, 15% pulley, CAI and a Unichip added to the ECU. Throughout the last four years I gradually added the GP intercooler, Milltek exhaust, Sprint Booster, Jan tune and last week the JCW head. I've never changed the iridium plugs since I purchased the car. The plugs had 35,000 miles on it until the head spit one of them out leading me to replace the head. Are there different temperature Iridium plugs? I can check the receipt I got from the original owner to get a part number for the iridium plugs it had installed.

 

You could bump up to 380cc injectors without an ECU tune, any bigger though and you will need a tune, with your mods you should already be running at least 380 injectors because the stock injectors are totally maxed out duty for sure.

 

Hmmm...that makes sense.

 

This is exactly why we don't recommend the Iridium plugs, they are always the ones that blow out the head.
But the dealer told you wrong you should have the colder heat range plugs in the car. ALL the R53 JCW tuning kits had the cooler JCW plugs if they were dealer installed or factory installed.

 

Plus your car was TUNED BY JAN WITH COOLER PLUGS...custom tunes tend to not have lots of flexibility to changes...you already have a different head...a slightly better flowing one...
Imo you should probably retune.....or risk a burnt valve from being lean from the extra airflow....
I would 100% use the jcw heat range plugs ( one step cooler than the s).

 

Have heard some good things on these plugs but have not personally tried them.


http://www.sneed4speed.com/mini-spar...4-brisk-lgs-t/

 

Maybe to be on the safe side I should just install the 380 injectors if I don't need to get it retuned and add the JCW plugs along with it? I read that your shop sells the same JCW plugs minus the JCW label (NGK version) at a reasonable price?

 

Since your car was tuned with the stock oem injectors putting the larger ones in without another tune is not advisable. Swap in plugs that are one range colder & call it good. Just my .02.

 

Thank you all for the information.

 

After interacting with you guys and checking a few other forums, the consensus seems to be to go with colder plugs. I also checked with MINI of South Atlanta who has a great parts website and they show two JCW upgrades for an 06 R53. 200hp and 210hp. The difference between both is the 210 adds bigger injectors. Both have the cooler JCW plugs. I ran that by my dealer and they finally agreed to swap out the plugs for the JCW at their cost.

 

I don't have a JCW, but have a 15% pulley, intake & exhaust. Been running the regular heat range for 114,000 miles. No problems for me. Using one step colder will not hurt a thing, same for the oem non-JCW range. Flip a coin. Nice of your dealer to swap them out for you.